Virtualized communication device and method therefor

ABSTRACT

An object is to provide a communication system capable of preventing a number of control signals, which could occur in a mobile communication network, from occurring when a VM is deleted in a node device without suspending a service. A communication system according to the present invention includes a communication device  1 , and a communication device  2  configured to control a plurality of sessions set between the communication devices  1  and  2  by using a plurality of VMs, in which the communication device  2  notifies, by using a determination that a plurality of sessions that are controlled between the communication device  1  and a VM  3  should be controlled in a VM  4  different from the VM  3  as a trigger, the communication device  1  of identification information used in the VM  4  and updates the sessions.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 16/590,792 filed on Oct. 2, 2019, which is acontinuation application of U.S. patent application Ser. No. 16/041,311filed on Jul. 20, 2018, which is a continuation application of U.S.patent application Ser. No. 15/118,304 filed on Aug. 11, 2016, whichissued as U.S. Pat. No. 10,057,355, which is a National Stage Entry ofinternational application PCT/JP2015/000427, filed on Jan. 30, 2015,which claims the benefit of priority from Japanese Patent Application2014-025566 filed on Feb. 13, 2014, the disclosures of all of which areincorporated in their entirety by reference herein.

TECHNICAL FIELD

The present invention relates to a communication system, a communicationdevice, a communication method, and a program. In particular, thepresent invention relates to a communication system including acommunication device that relays communication between terminals, acommunication device, a communication method, and a program.

BACKGROUND ART

A communication network includes a plurality of relay devices in orderto carry out communication between terminal devices. For example, in the3GPP (3rd Generation Partnership Project) for laying down standardspecifications for mobile communication networks, they are examining anetwork configuration in which user traffic and control traffic arerelayed by using node devices such as MMEs (Mobility ManagementEntities), SGWs (Serving Gateways), and PGWs (Packet Data NetworkGateways).

In recent years, it has been examined to efficiently use resources of anetwork by virtualizing node devices forming the network. For example, acase where a node device uses a VM (Virtual Machine) for each interfacethrough which the node device connects with another node device isexplained hereinafter. When traffic between the node device and theother node device increases, a VM for performing communication with theother node device is added in the node device. Further, when the trafficbetween the node device and the other node device decreases, a VM forperforming communication with the other node device is deleted and thedeleted VM may be added (i.e., reused) as a VM that used for performingcommunication with another node device. The VM may be, for example, acommunication resource, such as an internal memory, disposed inside thenode device. Further, the VM is used as a partial element for formingthe node device. That is, the above-described example is based on theprecondition that a plurality of interfaces are used as partial elementsin the node device and the VM corresponds to a communication resourceconstituting one of the interfaces.

In this way, by adding or deleting a VM according to the amount oftraffic processed by the node device or according to other conditions,the communication resources in the network can be efficiently used. InNon-patent Literature 1, virtualization in a network or in a node deviceis specified as NFV (Network Functions Virtualization).

Note that examples of the main factor for adding a VM in a node deviceinclude a case where there is a possibility of the occurrence ofcongestion in the node device or in the whole network due to an increasein traffic or the like. When there is a possibility of the occurrence ofcongestion, the increase in traffic can be handled by adding a VM. Forexample, in the case where a mobile communication network is taken intoconsideration, traffic that is transmitted from a terminal device due tothe occurrence of an event such as an ATTACH in which upon power-on ofthe terminal device, the terminal device connects to the mobilecommunication network or a handover that occurs as the terminal devicemoves flows into a newly-added VM.

On the other hand, examples of the main factor for deleting a VM in anode device include a purpose of preventing wasteful use ofcommunication resources when the processing capacity of the node deviceconsiderably surpasses the traffic capacity thereof. That is, it ispossible to reduce the power consumption and reduce the communicationresources by eliminating electric power supplied to a VM that has beenexcessively (or wastefully) used.

CITATION LIST Non Patent Literature

-   Non-patent Literature 1: “Network Functions Virtualisation—Update    White Paper” Oct. 15-17, 2013 at the “SDN and OpenFlow World    Congress”, Frankfurt-Germany-   Non-patent Literature 2: 3GPP TS 23.401 V12.3.0 (2013-12) 3rd    Generation Partnership Project; Technical Specification Group    Services and System Aspects; General Packet Radio Service (GPRS)    enhancements for Evolved Universal Terrestrial Radio Access Network    (E-UTRAN) access (Release 12)

SUMMARY OF INVENTION Technical Problem

Data related to a subscriber, data related to a session, or the like isassociated with a VM that is used inside a node device such as an MME,an SGW and a PGW. Therefore, in order to delete a VM without suspendinga mobile communication service provided to a subscriber, it is necessaryto transfer data related to the subscriber, date related to a session,or the like to another VM and then delete the original VM with which thedate related to the subscriber or the like is no longer associated.However, there is a problem that there are no specifications for such anoperation in the standard specified in the 3GPP or other communicationstandards.

An object of the present invention is to provide a communication system,a communication device, a communication method, and a program capable ofpreventing a number of control signals, which could occur in a mobilecommunication network, from occurring when a VM is deleted in a nodedevice without suspending a service.

Solution to Problem

A communication system according to a first aspect of the presentinvention includes: a first communication device, and a secondcommunication device configured to control a plurality of sessions setbetween the first and second communication devices by using a pluralityof VMs, in which the second communication device notifies, by using adetermination that a plurality of sessions that are controlled betweenthe first communication device and a first VM among the plurality of VMsshould be controlled in a second VM among the plurality of VMs differentfrom the first VM as a trigger, the first communication device ofidentification information used in the second VM and updates thesessions.

A communication device according to a second aspect of the presentinvention includes a control unit, the control unit being configured to:control a plurality of sessions set between the communication device andanother communication device by using a plurality of VMs; and notify, byusing a determination that a plurality of sessions that are controlledbetween the another communication device and a first VM among theplurality of VMs should be controlled in a second VM among the pluralityof VMs different from the first VM as a trigger, the anothercommunication device of identification information used in the second VMand update the sessions.

A communication method according to a third aspect of the presentinvention includes: controlling a plurality of sessions set with anothercommunication device by using a plurality of VMs; determining that aplurality of sessions that are controlled between the anothercommunication device and a first VM among the plurality of VMs should becontrolled in a second VM among the plurality of VMs different from thefirst VM; notifying the another communication device of identificationinformation used in the second VM; and updating the sessions.

A program according to a fourth aspect of the present invention causes acomputer to execute: controlling a plurality of sessions set withanother communication device by using a plurality of VMs; determiningthat a plurality of sessions that are controlled between the anothercommunication device and a first VM among the plurality of VMs should becontrolled in a second VM among the plurality of VMs different from thefirst VM; notifying the another communication device of identificationinformation used in the second VM; and updating the sessions.

Advantageous Effects of Invention

According to the present invention, it is possible to provide acommunication system, a communication device, a communication method,and a program capable of preventing a number of control signals, whichcould occur in a mobile communication network, from occurring when a VMis deleted in a node device without suspending a service. Further, thepresent invention can also be applied to an operation in which when a VMis added, rather than being deleted, a plurality of sessions aretransferred to the added VM.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a configuration diagram of a communication system accordingto a first exemplary embodiment;

FIG. 2 is a configuration diagram of an EPS (Evolved Packet System)according to a second exemplary embodiment;

FIG. 3 is a configuration diagram of an EPS (Evolved Packet System)according to a first exemplary embodiment;

FIG. 4 is a configuration diagram of a 2G/3G communication network inaccordance with 3GPP according to the first exemplary embodiment;

FIG. 5 is a configuration diagram of a communication network specifiedas PCC (Policy and Charging Control) in 3GPP according to the firstexemplary embodiment;

FIG. 6 is a configuration diagram of a communication networkcorresponding to CSFB (Circuit Switched Fall Back) in 3GPP according toa second exemplary embodiment;

FIG. 7 is a configuration diagram of a Virtualized MME 100 according tothe second exemplary embodiment;

FIG. 8 is a configuration diagram of a Virtualized SGW 120 according tothe second exemplary embodiment;

FIG. 9 is a configuration diagram of a Virtualized PGW 140 according tothe second exemplary embodiment;

FIG. 10 is a configuration diagram of a Virtualized SGSN 160 accordingto the second exemplary embodiment;

FIG. 11 is a configuration diagram of a Virtualized GGSN 180 accordingto the second exemplary embodiment;

FIG. 12 is a configuration diagram of a Virtualized eNodeB 200 accordingto the second exemplary embodiment;

FIG. 13 is a configuration diagram of a Virtualized RNC 210 according tothe second exemplary embodiment;

FIG. 14 is a diagram for explaining a transfer of a session when an S11VM 106 of the Virtualized MME 100 according to the second exemplaryembodiment is deleted;

FIG. 15 is a diagram for explaining the transfer of the session when theS11 VM 106 of the Virtualized MME 100 according to the second exemplaryembodiment is deleted;

FIG. 16 is a diagram for explaining a session transfer process performedwhen an S5/S8-C VM according to the second exemplary embodiment isdeleted;

FIG. 17 is a diagram for explaining the session transfer processperformed when the S5/S8-C VM according to the second exemplaryembodiment is deleted;

FIG. 18 is a diagram for explaining the session transfer processperformed when the S5/S8-C VM according to the second exemplaryembodiment is deleted;

FIG. 19 is a diagram for explaining the session transfer processperformed when the S5/S8-C VM according to the second exemplaryembodiment is deleted;

FIG. 20 is a diagram for explaining a session transfer process performedwhen an S5/S8-U VM according to the second exemplary embodiment isdeleted;

FIG. 21 is a diagram for explaining the session transfer processperformed when an S5/S8-U VM according to the second exemplaryembodiment is deleted;

FIG. 22 is a diagram for explaining the session transfer processperformed when an S5/S8-U VM according to the second exemplaryembodiment is deleted;

FIG. 23 is a diagram for explaining the session transfer processperformed when an S5/S8-U VM according to the second exemplaryembodiment is deleted;

FIG. 24 shows a flow of a process that is performed when a VM of aVirtualized MME according to the second exemplary embodiment is deleted;

FIG. 25 shows a flow of the process that is performed when the VM of theVirtualized MME according to the second exemplary embodiment is deleted;

FIG. 26 shows a flow of the process that is performed when the VM of theVirtualized MME according to the second exemplary embodiment is deleted;

FIG. 27 shows a flow of the process that is performed when the VM of theVirtualized MME according to the second exemplary embodiment is deleted;

FIG. 28 shows a flow of the process that is performed when the VM of theVirtualized MME according to the second exemplary embodiment is deleted;

FIG. 29 shows a flow of the process that is performed when the VM of theVirtualized MME according to the second exemplary embodiment is deleted;

FIG. 30 shows a flow of a process that is performed when a VM of aVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 31 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 32 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 33 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 34 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 35 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 36 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 37 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 38 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 39 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 40 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 41 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 42 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 43 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 44 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 45 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 46 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 47 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 48 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 49 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 50 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 51 shows a flow of the process that is performed when the VM of theVirtualized SGW according to the second exemplary embodiment is deleted;

FIG. 52 shows a flow of a process that is performed when a VM of aVirtualized PGW according to the second exemplary embodiment is deleted;

FIG. 53 shows a flow of the process that is performed when the VM of theVirtualized PGW according to the second exemplary embodiment is deleted;

FIG. 54 shows a flow of the process that is performed when the VM of theVirtualized PGW according to the second exemplary embodiment is deleted;

FIG. 55 shows a flow of the process that is performed when the VM of theVirtualized PGW according to the second exemplary embodiment is deleted;

FIG. 56 shows a flow of the process that is performed when the VM of theVirtualized PGW according to the second exemplary embodiment is deleted;

FIG. 57 shows a flow of the process that is performed when the VM of theVirtualized PGW according to the second exemplary embodiment is deleted;

FIG. 58 shows a flow of the process that is performed when the VM of theVirtualized PGW according to the second exemplary embodiment is deleted;

FIG. 59 shows a flow of the process that is performed when the VM of theVirtualized PGW according to the second exemplary embodiment is deleted;

FIG. 60 shows a flow of the process that is performed when the VM of theVirtualized PGW according to the second exemplary embodiment is deleted;

FIG. 61 shows a flow of the process that is performed when the VM of theVirtualized PGW according to the second exemplary embodiment is deleted;

FIG. 62 shows a flow of a process that is performed when a VM of aVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 63 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 64 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 65 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 66 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 67 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 68 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 69 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 70 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 71 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 72 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 73 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 74 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 75 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 76 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 77 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 78 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 79 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 80 shows a flow of the process that is performed when the VM of theVirtualized SGSN according to the second exemplary embodiment isdeleted;

FIG. 81 shows a flow of a process that is performed when a VM of aVirtualized GGSN according to the second exemplary embodiment isdeleted;

FIG. 82 shows a flow of the process that is performed when the VM of theVirtualized GGSN according to the second exemplary embodiment isdeleted;

FIG. 83 shows a flow of the process that is performed when the VM of theVirtualized GGSN according to the second exemplary embodiment isdeleted;

FIG. 84 shows a flow of the process that is performed when the VM of theVirtualized GGSN according to the second exemplary embodiment isdeleted;

FIG. 85 shows a flow of the process that is performed when the VM of theVirtualized GGSN according to the second exemplary embodiment isdeleted;

FIG. 86 shows a flow of the process that is performed when the VM of theVirtualized GGSN according to the second exemplary embodiment isdeleted;

FIG. 87 shows a flow of the process that is performed when the VM of theVirtualized GGSN according to the second exemplary embodiment isdeleted;

FIG. 88 shows a flow of the process that is performed when the VM of theVirtualized GGSN according to the second exemplary embodiment isdeleted;

FIG. 89 shows a flow of the process that is performed when the VM of theVirtualized GGSN according to the second exemplary embodiment isdeleted;

FIG. 90 shows a flow of the process that is performed when the VM of theVirtualized GGSN according to the second exemplary embodiment isdeleted;

FIG. 91 shows a flow of a process that is performed when a VM of aVirtualized eNodeB according to the second exemplary embodiment isdeleted;

FIG. 92 shows a flow of the process that is performed when the VM of theVirtualized eNodeB according to the second exemplary embodiment isdeleted;

FIG. 93 shows a flow of the process that is performed when the VM of theVirtualized eNodeB according to the second exemplary embodiment isdeleted;

FIG. 94 shows a flow of the process that is performed when the VM of theVirtualized eNodeB according to the second exemplary embodiment isdeleted;

FIG. 95 shows a flow of a process that is performed when a VM of aVirtualized RNC according to the second exemplary embodiment is deleted;

FIG. 96 shows a flow of the process that is performed when the VM of theVirtualized RNC according to the second exemplary embodiment is deleted;

FIG. 97 shows a flow of the process that is performed when the VM of theVirtualized RNC according to the second exemplary embodiment is deleted;

FIG. 98 shows a flow of the process that is performed when the VM of theVirtualized RNC according to the second exemplary embodiment is deleted;

FIG. 99 shows a flowchart for explaining an outline of a process flowfor deleting a VM in an MME and constructing a new session in acomparative example;

FIG. 100 shows a flow of a PDN connection resetting process in thecomparative example; and

FIG. 101 shows a flow of the PDN connection resetting process in thecomparative example.

DESCRIPTION OF EMBODIMENTS Explanation of Comparative Example

A comparative example that the inventors have examined before conceivinga communication system according to an exemplary embodiment is explainedhereinafter with reference to FIGS. 99 to 101 . In the comparativeexample, a procedure in which a VM in an MME is deleted and a newsession is constructed in accordance with the procedure specified in thecurrent 3GPP is explained. Further, in FIGS. 99 to 101 , explanationsare given by using a UE (User Equipment), an eNB (evolved NB), an MME,an SGW, a PGW, a PCRF (Policy and Charging Rules Function) and an HSS(Home Subscriber Server), which are devices specified in the 3GPP.

Firstly, an outline of a process flow from the deletion of a VM in anMME to the construction of a new session is explained with reference toFIG. 99 . When it is determined that a session (e.g., a PDN connection)set in the VM of the MME should be transferred, the MME starts anMME-initiated Detach procedure (Non-patent Literature 2: section5.3.8.3) (S1001). Upon the start-up of the MME-initiated Detachprocedure, a UE (User Equipment) changes its state to a Detach state (astate in which the UE is detached from the network). Next, the UE, whichis in the Detach state, starts an E-UTRAN Initial Attach process(Non-patent Literature 2: section 5.3.2.1) (S1002). Next, when the MMEreceives an ATTACH signal, the MME constructs an S11 session by using anMME different from the MME in which the VM is to be deleted (S1003). Inthis way, the transfer of the PDN connection is completed.

By performing the process in the step S1001, information about the UEdetached from the MME can be deleted. Further, in an SGW, a PGW, or thelike, by detaching the UE, the information about the UE detached fromthe respective node device can be deleted.

Next, a flow of process for re-setting a PDN connection performed in thesteps S1002 and S1003 in FIG. 99 is explained in a concrete manner withreference to FIGS. 100 and 101 .

Firstly, a UE transmits an Attach request message to an MME (S1101).Next, in a step S1002, the UE is authenticated (S1102). Next, the MMEtransmits a Create Session Request (MME-S11 IP address, MME-S11 TEID)message to an SGW (S1103).

Next, the SGW transmits the Create Session Request (SGW-S5 IP address,SGW-S5 TEID) message to a PGW (S1104). Next, a QoS negotiation processis performed between the PGW and a PCRF (S1105). Next, the PGW transmitsa Create Session Response (PGW-S5 IP address, PGW-S5 TEID) message tothe SGW (S1106). By transmitting/receiving the messages in the stepsS1104 and S1106, tunnel information of each of the SGW and the PGW isexchanged between the SGW and the PGW. As a result, a PDN connection,which is used in an S5 interface, is established.

Next, the SGW transmits the Create Session Response (SGW-S11 IP address,SGW-S11 TEID, SGW-S1-U IP address, SGW-S1-U TEID) message to the MME(S1107). By transmitting/receiving the messages in the steps S1103 andS1107, tunnel information of each of the SGW and the MME is exchangedbetween the SGW and the MME. As a result, a PDN connection, which isused in an S11 interface and an S1-U interface, is established.

Next, the MME transmits an Initial context setup Request (SGW-S1-U IPaddress, SGW-S1-U TEID) message to an eNB (S1108). Next, in a stepS1109, a radio setting between the UE and the eNB is made. Next, the eNBtransmits the Initial context setup Request (eNB-S1-U IP address,eNB-S1-U TEID) message to the MME (S1110). Next, the MME transmits aModify Bearer Request (eNB-S1-U IP address, eNB-S1-U TEID) to the SGW(S1111). By transmitting/receiving the messages in the steps S1107,S1108, S1110 and S1111, tunnel information of each of the eNB and theSGW is exchanged between the eNB and the SGW. As a result, a PDNconnection, which is used in the S1-U interface, is established.

Next, the SGW transmits a Modify Bearer Response message to the MME(S1112).

As explained above, the UE can set the S5 PDN connection, the S1 PDNconnection, and the S1-U PDN connection by temporarily changing itsstate to the Detach state and then performing the steps S1101 to S1112.

However, in the process explained above in the comparative example, theMME needs to make the UE temporarily change its state to the Detachstate to delete the VM and then perform the steps S1101 to S1112 beforethe UE changes its state to the Attach state. As a result, the number ofsignals increases. Further, as the number of UEs increases, the numberof signals that are transmitted/received in the mobile communicationnetwork increases even further. Therefore, there is a concern that asthe number of signals increases, congestion could occur. Further, whenthe UE is detached, the mobile communication service for the UE isinterrupted. As a result, there is a concern that the service qualitycould significantly deteriorate. In exemplary embodiments describedbelow, a communication system and a communication process flow in whicha VM is deleted by transmitting/receiving the required minimum number ofmessages to/from a neighboring node(s) are explained.

First Exemplary Embodiment

Exemplary embodiments according to the present invention are explainedhereinafter with reference to the drawings. A configuration example of acommunication system according to a first exemplary embodiment of thepresent invention is explained with reference to FIG. 1 . Thecommunication system shown in FIG. 1 includes communication devices 1and 2.

Each of the communication devices 1 and 2 is a computer device thatoperates by having a CPU (Center Processing Unit) execute a programstored in a memory, or includes a plurality of VMs each of whichoperates by executing a program stored in a memory. Further, each of thecommunication devices 1 and 2 may be an MME, an SGW, a PGW, or the like,which are node devices specified in the 3GPP. Further, each of thecommunication devices 1 and 2 may be a NodeB or an eNodeB, which arebase station devices, or an SGSN (Serving General packet radio serviceSupport Node), a GGSN (Gateway General packet radio service SupportNode), an RNC (Radio Network Controller), or the like, which form theso-called “second-generation” network.

The communication device 2 sets a plurality of sessions between thecommunication device 2 and the communication device 1 and communicateswith the communication device 1. The plurality of sessions may be, forexample, sessions set for respective terminal devices, or sessions setfor respective groups of terminal devices when a plurality of terminaldevices are divided into the groups. Each session may include routeinformation between the communication devices 1 and 2, informationnecessary for carrying out communication with a counterpartcommunication device, information about a terminal device, and the like.The information about a terminal device may be, for example, anidentifier of the terminal device, information about a communicationspeed permitted for the terminal device, and the like.

The communication device 2 sets a plurality of sessions by using a VM 3or a VM 4. In FIG. 1 , the dotted-line arrow indicates a state where thecommunication device 1 sets a plurality of sessions with VM 3 and thesolid-line arrow indicates a state where the communication device 1 setsa plurality of sessions with VM 4. These arrows indicate that thecommunication device 1 transfers the sessions set between thecommunication device 1 and the VM 3 to the VM 4.

The VMs 3 and 4 are formed by a plurality of communication resourcessuch as different CPUs, memories, and network interfaces. In FIG. 1 ,the VM 3 includes communication resources 5 and 6, and the VM 4 includescommunication resources 7 and 8. When the communication device 2 isvirtualized, the VMs 3 and 4 become partial elements constituting thecommunication device 2. The resources corresponding to the VMs 3 and 4may be separately supplied with electric power. That is, the electricpower that is consumed when only one of the VMs 3 and 4 is used can bereduced from the electric power that is consumed when the VMs 3 and 4are both used.

The communication device 2 determines that the state in which aplurality of sessions set between the communication devices 1 and 2 byusing the VM 3 should be changed so that the plurality of sessions setbetween the communication devices 1 and 2 are controlled by using the VM4. For example, the communication device 2 may change the VM thatcontrols the plurality of sessions set between the communication devices1 and 2 according to an instruction entered by a supervisor or the likewho manages the communication device 2, or change the VM that controlsthe plurality of sessions set between the communication devices 1 and 2according to an instruction signal input from other operation devices orthe like.

By using the determination that the state in which a plurality ofsessions set between the communication devices 1 and 2 are controlled byusing the VM 3 should be changed so that the plurality of sessions setbetween the communication devices 1 and 2 are controlled by using the VM4 as a trigger, the communication device 2 notifies the communicationdevice 1 of identification information used in the VM 4 and updates thesessions. The identification information is information by which thefact that the control is performed in the VM 4 is uniquely recognized inthe communication device 2.

The situation for the determination that the state in which a pluralityof sessions set between the communication devices 1 and 2 are controlledby using the VM 3 should be changed so that the plurality of sessionsset between the communication devices 1 and 2 are controlled by usingthe VM 4 includes the following situations. For example, thecommunication device 2 deletes the VM 3 and thereby transfers theplurality of sessions set in the VM 3 to the VM 4. Alternatively, thecommunication device 2 adds a new VM 4 and hence transfers some or allof the plurality of sessions set in the VM 3 to the VM 4.

As explained above, when the communication device 2 changes the VM thatcontrols a plurality of sessions set between the communication devices 1and 2, the communication device 2 can notify the communication device 1of the identification information used in the new VM after the change.Upon receiving the identification information of the new VM after thechange from the communication device 2, the communication device 1 candesignate the VM 4 as a destination when data is transmitted to thecommunication device 2 at and after the next time. In this way, it ispossible to transfer data that has been originally transmitted from thecommunication device 1 to the VM 3 to the VM 4.

That is, by changing the sessions between the communication devices 1and 2 without detaching the terminal device, it is possible to deletethe VM 3 and transfer the traffic transmitted from the communicationdevice 1 to the VM 4. That is, since the control signals that occur dueto the deletion of the VM 3 are transmitted/received only between thecommunication devices 1 and 2, it is possible to prevent a large numberof control signals from being transmitted/received in the network.

Second Exemplary Embodiment

Next, a configuration example of a communication network according tothe second exemplary embodiment of the present invention is explainedwith reference to FIGS. 2 to 6 . FIGS. 2 to 6 are configuration examplesof a communication network specified in the 3GPP.

FIG. 2 is a configuration example of an EPS (Evolved Packet System) in acase where a UE does not perform roaming. The EPS shown in FIG. 2includes a UE (User Equipment) 10, an E-UTRAN (Evolved UniversalTerrestrial Radio Access Network) 11, an MME 12, an SGW 13, an SGSN(Serving GPRS Support Node) 14, an HSS (Home Subscriber Server) 15, aPGW 16, a PCRF (Policy and Charging Rules Function) 17, and an operatornetwork 18. The operator network 18 may be, for example, an IMS (IPMultimedia Subsystem), a PSS (Packet Switch Streaming), or the like. Thesymbols LTE-Uu, S1-U, S3, Gx, and so on specified between node devicesin the figure represent the names of the interfaces between the nodedevices. This is also applied to FIG. 3 and the subsequent figures.Further, the SGSN 14 is connected to an UTRAN and a GERAN (GSM(Registered Trademark) EDGE Radio Access Network), and the SGW 13 isconnected to the UTRAN. Each of the E-UTRAN 11, the UTRAN and the GERANrepresents a wireless network and includes a base station device and thelike.

FIG. 3 is a configuration example of an EPS (Evolved Packet System) in acase where a UE is performing roaming. The EPS shown in FIG. 3 include aUE 10, an E-UTRAN 11, an MME 12, an SGW 13, an SGSN 14, an HSS 21, a PGW22, a PCRF 23, and an operator network 24. In this figure, a UE 10 islocated in a VPLMN (Visited Public Land Mobile Network). Therefore, theMME 12 communicates with the HSS 21 located in an HPLMN (Home PublicLand Mobile Network), and the SGW 13 communicates with the PGW 22located in the HPLMN. Note that the main difference between FIG. 3 andFIG. 2 is that while the interface between the SGW 13 and the PGW 22 isan interface S8 in FIG. 3 , the interface between the SGW 13 and the PGW16 is an interface S5 in FIG. 2 . Details of FIGS. 2 and 3 are describedin the specifications of 3GPP TS23.401.

FIG. 4 shows a configuration example of the so-called “2G” or “3G”communication network in the 3GPP. The communication network shown inFIG. 4 includes a TE (Terminal Equipment) 31, an MT (Mobile Terminal)32, a UTRAN 33, an SGSN 34, a TE 35, an MT 36, a BSS (Base StationSystem) 37, an SGSN 38, a GGSN (Gateway GPRS Support Node) 39, a GGSN40, an MSC (Mobile Switching Center)/VLR (Visitor Location Register) 41,an SMS-GMSC and an SMS-IWMSC (Inter-Working Mobile Switching Centre) 42,an SMS-SC 43, a gsmSCF (gsm Service Control Function) 44, a CGF(Charging Gateway Function) 45, an EIR (Equipment Identity Register) 46,a Billing System 47, a TE 48, and an HLR 49. The dotted lines in thefigure indicate Signaling interfaces for transmitting control signals,and the solid lines indicates Signaling and Data Transfer Interfaces fortransmitting control signals and user data. Details of FIG. 4 aredescribed in the specifications of 3GPP TS23.060.

FIG. 5 shows a communication network specified as PCC (Policy andCharging Control) in the 3GPP. The communication network shown in FIG. 5includes a BBERF (Bearer Binding and Event Reporting Function) 51, aV-PCRF (Visited-PCFR) 52, an SPR (Subscriber Profile Repository) 53, anH-PCRF (Home-PCRF) 54, a PCEF (Policy and Charging Enforcement Function)55, a Gateway 56, an AF (Application Function) 57, an OCS (OnlineCharging System) 58, a TDF (Traffic Detection Function) 59, and an OFCS(Offline Charging System) 60. Details of FIG. 5 are described in thespecifications of 3GPP TS23.203.

FIG. 6 shows a configuration example of a communication networkcorresponding to CSFB (Circuit Switched Fall Back) in the 3GPP. Thecommunication network shown in FIG. 6 includes a UE 71, an E-UTRAN 72, aGERAN 73, a UTRAN 74, an SGSN 75, an MME 76, and an MSC Server 77.Details of FIG. 6 are described in the specifications of 3GPP TS23.272.

Next, a configuration example of a Virtualized MME 100 according to thesecond exemplary embodiment is explained with reference to FIG. 7 . TheVirtualized MME 100 is a name given to an MME formed by a plurality ofVMs. The Virtualized MME 100 is configured so as to use a VM(s) for anoperation necessary for each interface in the MME 12 shown in FIG. 2 orin the MME 76 shown in FIG. 6 . The Virtualized MME 100 includes S6a VMs101-103, S11 VMs 104-106, an SGs VM 107, an SGs VM 108, S1-MME VMs109-111, and a control unit 15. Note that the number of VMs used in eachinterface in the figure is just an example. That is, the number of VMsmay be arbitrarily determined. This is also applied to other figuresexplained below.

The S6a VMs 101-103 provide functions necessary for controlling theinterface between the Virtualized MME 100 and the HSS 15 shown in FIG. 2or the HSS 21 shown in FIG. 3 . Examples of the function include anacquisition of subscriber data. The S11 VMs 104-106 provide functionsnecessary for controlling sessions set between the Virtualized MME 100and the SGW 13 shown in FIG. 2 . The SGs VM 107 and the SGs VM 108provide functions necessary for controlling sessions set between theVirtualized MME 100 and the MSC server 77 shown in FIG. 6 . The S1-MMEVMs 109-111 provide functions necessary for controlling sessions setbetween the Virtualized MME 100 and the E-UTRAN 11 shown in FIG. 1 . TheE-UTRAN 11 may be, for example, an eNB (evolved NB), which is a basestation device.

For example, each VM allocates a predetermined memory area for eachsession. Therefore, the maximum number of sessions that can set in eachVM may be determined according to the memory area or the memorycapacity. The above-described matters for the VMs shown in the figureare also applied to VMs that are specified below.

The control unit 115 controls the number of sessions, determines thetransfer destination of sessions set in the VM to be deleted, controlscommunication through each VM, and so on. Further, the control unit 115may monitor the load state of each VM. Then, for example, when a nightcomes and the number of sessions is decreased beyond the predeterminednumber of sessions determined by a given VM, the control unit 115 maydetermine that the remaining sessions left in that VM should betransferred to other VMs, determine their transfer destinations, and/ordetermine that they are distributed over a plurality of VMs withconsideration given to the load state of the transfer destinations. Theabove-described matters are also applied to control units of otherdevices described below.

Next, a configuration example of a Virtualized SGW 120 according to thesecond exemplary embodiment is explained with reference to FIG. 8 . TheVirtualized SGW 120 is configured so as to use a VM(s) for aninterface(s) in the SGW 13 shown in FIG. 2 . The Virtualized SGW 120includes a Gxx VM 121, a Gxx VM 122, an S5/S8-C VM 123, an S5/S8-C VM124, an S5/S8-U VM 125, an S5/S8-U VM 126, an S11 VM 127, an S11 VM 128,an S1-U VM 129, an S1-U VM 130, an S12 VM 131, an S12 VM 132, and acontrol unit 135.

The Gxx VMs 121 and 122 are interfaces used for sessions set between theVirtualized SGW 120 and the V-PCRF 52 when the Virtualized SGW 120 has afunction of the BBERF 51 shown in FIG. 5 . The S5/S8-C VMs 123 and 124are interfaces used for sessions set between the Virtualized SGW 120 andthe PGW 16 shown in FIG. 2 or the PGW 22 shown in FIG. 3 .

The S11 VMs 127 and 128 are interfaces used for sessions set between theVirtualized SGW 120 and the MME 12 shown in FIG. 2 . The S1-U VMs 129and 130 are interfaces used for sessions set between the Virtualized SGW120 and the E-UTRAN 11 shown in FIG. 2 . The E-UTRAN 11 may be, forexample, an eNB (evolved NB), which is a base station device. The S12VMs 131 and 132 are interfaces used for sessions set between theVirtualized SGW 120 and the UTRAN. The UTRAN may be, for example, aNodeB, which is a base station device.

Next, a configuration example of a Virtualized PGW 140 according to thesecond exemplary embodiment is explained with reference to FIG. 9 . TheVirtualized PGW 140 is configured so as to use a VM(s) for aninterface(s) in the PGW 16 shown in FIG. 2 or the PGW 22 shown in FIG. 3.

The Virtualized PGW 140 includes Gx VMs 141-143, Gy/Gz VMs 144-146, SGiVMs 147 and 148, S5/S8-C VMs 149 and 150, S5/S8-U VMs 151 and 152, and acontrol unit 155.

The Gx VMs 141-143 are interfaces used for sessions set between theVirtualized PGW 140 and the PCRF 17 shown in FIG. 2 or the PCRF 23 shownin FIG. 3 . The Gy/Gz VMs 144-146 are interfaces used for sessions setbetween the Virtualized PGW 140 and the OCS 58 or the OFCS 60 shown inFIG. 5 when the Virtualized PGW 140 has a function of the PCEF 55.

The SGi VMs 147 and 148 are interfaces used for sessions set between theVirtualized PGW 140 and the operator network 18 shown in FIG. 2 or theoperator network 24 shown in FIG. 3 . The S5/S8-C VMs 149 and 150 areinterfaces used for sessions set for C-Plane data communication betweenthe Virtualized PGW 140 and the SGW 13. The S5/S8-U VM 151 and 152 areinterfaces used for sessions set for U-Plane data communication betweenthe Virtualized PGW 140 and the SGW 13 shown in FIG. 2 .

Next, a configuration example of a Virtualized SGSN 160 according to thesecond exemplary embodiment is explained with reference to FIG. 10 . TheVirtualized SGSN 160 is configured so as to use a VM(s) for aninterface(s) in the SGSN 14 shown in FIG. 2 or the SGSN 34 shown in FIG.4 .

The Virtualized SGSN 160 includes S4-C VMs 161 and 162, Gn-C VMs 163 and164, Gn-U VMs 165 and 166, Gr/S6d VMs 167 and 168, S4-U VMs 169 and 170,Gs VMs 171 and 172, Iu-C VMs 173 and 174, Iu-U VMs 175 and 176, and acontrol unit 177.

The S4-C VMs 161 and 162 are interfaces used for sessions set forC-Plane data communication between the Virtualized SGSN 160 and the SGW13 shown in FIG. 2 . The S4-U VMs 169 and 170 are interfaces used forsessions set for U-Plane data communication between the Virtualized SGSN160 and the SGW 13.

The Gn-C VMs 163 and 164 are interfaces used for sessions set forC-Plane data communication between the Virtualized SGSN 160 and the GGSN40. The Gn-U VMs 165 and 166 are interfaces used for sessions set forU-Plane data communication between the Virtualized SGSN 160 and the GGSN40 shown in FIG. 4 .

The Gr/S6d VMs 167 and 168 are interfaces used for sessions set betweenthe Virtualized SGSN 160 and the HLR 49 shown in FIG. 4 . The Gs VMs 171and 172 are interfaces used for sessions set between the VirtualizedSGSN 160 and the MSC/VLR 41.

The Iu-C VMs 173 and 174 are interfaces used for sessions set forC-Plane data communication between the Virtualized SGSN 160 and theUTRAN 33. The Iu-U VMs 175 and 176 are interfaces used for sessions setfor U-Plane data communication between the Virtualized SGSN 160 and theUTRAN 33 shown in FIG. 4 .

Next, a configuration example of a Virtualized GGSN 180 according to thesecond exemplary embodiment is explained with reference to FIG. 11 . TheVirtualized GGSN 180 is configured so as to use a VM(s) for aninterface(s) in the SGSN 14 shown in FIG. 2 or the SGSN 34 shown in FIG.4 .

The Virtualized GGSN 180 includes Gx VMs 181-183, Gy/Gz VMs 184-186, GiVMs 187 and 188, Gn-C VMs 189 and 190, Gn-U VMs 191 and 192, and acontrol unit 195.

The Gx VMs 181-183 are interfaces used for sessions set between theVirtualized GGSN 180 and the H-PCRF 54 when the Virtualized GGSN 180 hasa function of the PCEF 55. The Gy/Gz VMs 144-146 are interfaces used forsessions set between the Virtualized GGSN 180 and the OCS 58 or the OFCS60 when the Virtualized GGSN 180 has a function of the PCEF 55 shown inFIG. 5 .

The Gi VMs 187 and 188 are interfaces used for sessions set between theVirtualized GGSN 180 and an IP network to which a communication carrierprovides services unique to that carrier, or a PDN (Packet DeliveryNetwork) managed by other communication carriers.

The Gn-C VMs 189 and 190 are interfaces used for sessions set forC-Plane data communication between the Virtualized GGSN 180 and the SGSN34. The Gn-U VMs 191 and 192 are interfaces used for sessions set forU-Plane data communication between the Virtualized GGSN 180 and the SGSN34 shown in FIG. 4 .

Next, a configuration example of a Virtualized eNodeB 200 according tothe second exemplary embodiment is explained with reference to FIG. 12 .The Virtualized eNodeB 200 is configured so as to use a VM(s) for aninterface(s) in an eNodeB located in the E-UTRAN 11 shown in FIG. 2 .

The Virtualized eNodeB 200 includes S1-MME VMs 201-203, S1-U VMs204-206, an LTE-Uu 207, and a control unit 208.

The S1-MME VMs 201-203 are interfaces used for sessions set between theVirtualized eNodeB 200 and the MME 12 shown in FIG. 2 . The S1-U VMs204-206 are interfaces used for sessions set between the VirtualizedeNodeB 200 and the SGW 13 shown in FIG. 2 . The LTE-Uu 207 is aninterface used for sessions set between the Virtualized eNodeB 200 andthe UE 10.

Next, a configuration example of a Virtualized RNC 210 according to thesecond exemplary embodiment is explained with reference to FIG. 13 . TheVirtualized RNC 210 is configured so as to use a VM(s) for aninterface(s) in an RNC (Radio Network Controller) located in the UTRAN33 shown in FIG. 4 .

The Virtualized RNC 210 includes Iu-C VMs 211-213, Iu-U VMs 214-216, aUu 217, and a control unit 218.

The Iu-C VMs 211-213 are interfaces used for sessions set for C-Planedata communication between the Virtualized RNC 210 and the SGSN 34 shownin FIG. 4 . The Iu-U VMs 214-216 are interfaces used for sessions setfor U-Plane data communication between the Virtualized RNC 210 and theSGSN 34. The Uu 217 is an interface used for sessions set between theVirtualized RNC 210 and the MT 32 shown in FIG. 4 .

Next, a transfer of sessions that is performed when the S11 VM 106 ofthe Virtualized MME 100 is deleted is explained with reference to FIGS.14 and 15 . The deletion of a VM may be a suspension of the supply ofelectric power to the VM. FIG. 14 shows sessions set between theVirtualized MME 100 and the SGW 13 in which: 60,000 sessions are set inthe S11 VM 104; 80,000 sessions are set in the S11 VM 105; and 40,000sessions are set in the S11 VM 106. Specifically, sessions may be PDNconnections.

In FIG. 14 , when the S11 VM 106 is deleted, it is necessary to transferthe 40,000 sessions set in the S11 VM 106 to the S11 VMs 104 and 105.For this transfer, the Virtualized MME 100 may transfer the sessions inthe S11 VM 106 while taking the load states in the S11 VMs 104 and 105into consideration by using the control unit 115. For example, theVirtualized MME 100 may transfer the sessions in the S11 VM 106 so thatthe number of sessions in the S11 VM 104 and that in the S11 VM 105 areroughly equal to each other.

Specifically, the Virtualized MME 100 may transfer 30,000 sessions inthe S11 VM 106 to the S11 VM 104 and transfer 10,000 sessions in the S11VM 106 to the S11 VM 105. By doing so, as shown in FIG. 15 , each of theS11 VMs 104 and 105 has 90,000 sessions set therein and hence the loadsof them become equal to each other. Further, the Virtualized MME 100 mayperform management so that any new sessions that are generated duringthe session transfer operation from the S11 VM 106 to the S11 VMs 104and 105 are not set in the S11 VM 106.

The management of the number of sessions set in each VM, thedetermination of the transfer destination of the sessions set in the VMto be deleted, and the like may be performed by a control unit such as aCPU mounted in the Virtualized MME 100. In FIGS. 14 and 15 , an examplewhere the S11 VM 106 of the Virtualized MME 100 is deleted is explained.However, control similar to the control shown in FIGS. 14 and 15 may beperformed in the case where a VM other than the S11 VM 106 in theVirtualized MME 100 is deleted and a new VM is added, and in the casewhere a VM in other devices (such as the Virtualized SGW, PGW, SGSN, andGGSN) is deleted and a new VM is added.

Next, a process for transferring sessions performed when a VM is deletedaccording to the second exemplary embodiment is explained with referenceto FIGS. 16 to 19 . In FIGS. 16 to 19 , a process for deleting theS5/S8-C VM 123 of the Virtualized SGW 120 is explained.

FIG. 16 shows that a GTP-C signaling connection is set between theVirtualized MME 100 and the S11 VM 128 of the Virtualized SGW 120 andbetween the Virtualized PGW 140 and the S5/S8-C VM 123 of theVirtualized SGW 120.

FIG. 17 shows that when the S5/S8-C VM 123 is deleted, a Modify BearerRequest message and a Modify Bearer Response message aretransmitted/received between the S5/S8-C VM 123 and the Virtualized PGW140. Since the Virtualized PGW 140 receives the Modify Bearer Request,the Virtualized PGW 140 does not need to recognize that the S5/S8-C VM123 is deleted.

As shown in FIG. 18 , by transmitting/receiving the Modify BearerRequest and the Modify Bearer Response between the S5/S8-C VM 123 andthe Virtualized PGW 140, the GTP-C signaling connection between theVirtualized SGW 120 and the Virtualized PGW 140 is updated. That is, theGTP-C signaling connection between Virtualized SGW 120 and theVirtualized PGW 140, which has been originally set between the S5/S8-CVM 123 and the Virtualized PGW 140, is set between the S5/S8-C VM 124and the Virtualized PGW 140.

FIG. 19 shows that after all the sessions set in the S5/S8-C VM 123 aretransferred to the S5/S8-C VM 124, the S5/S8-C VM 123 is deleted.

Next, a process for transferring sessions performed when a VM is deletedaccording to the second exemplary embodiment is explained with referenceto FIGS. 20 to 23 . In FIGS. 20 to 23 , a process for deleting theS5/S8-U VM 125 of the Virtualized SGW 120 is explained.

FIG. 20 shows that a GTP-C signaling connection is set between theVirtualized MME 100 and the S1-U VM 129 of the Virtualized SGW 120 andbetween the Virtualized PGW 140 and the S5/S8-U VM 125 of theVirtualized SGW 120.

FIG. 21 shows that when the S5/S8-U VM 125 is deleted, a Modify BearerRequest message and a Modify Bearer Response message aretransmitted/received between the S5/S8-C VM 123 and the Virtualized PGW140. Note that the Modify Bearer Request message and the Modify BearerResponse message are transmitted/received through the S5/S8-C VM 123.Since the Virtualized PGW 140 receives the Modify Bearer Request, theVirtualized PGW 140 does not need to recognize that the S5/S8-U VM 125is deleted.

As shown in FIG. 22 , by transmitting/receiving the Modify BearerRequest and the Modify Bearer Response between the S5/S8-C VM 123 andthe Virtualized PGW 140, the GTP-C signaling connection between theVirtualized SGW 120 and the Virtualized PGW 140 is updated. That is, theGTP-C signaling connection between Virtualized SGW 120 and theVirtualized PGW 140 is set between the S5/S8-U VM 126 and theVirtualized PGW 140.

FIG. 23 shows that after all the sessions set in the S5/S8-U VM 125 aretransferred to the S5/S8-U VM 126, the S5/S8-U VM 125 is deleted.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 24 . FIG. 24 shows a process that is performed whenone of the S11 VMs 104-106 of the Virtualized MME 100 is deleted.

Firstly, the Virtualized MME 100 transmits a Modify Bearer Requestmessage to the Virtualized SGW 120 (S11). The Virtualized MME 100 setsan IP address indicating a VM at the transfer destination of thesessions and a TEID (Tunnel Endpoint ID) in the Modify Bearer Requestmessage. The TEID is an identifier indicating the end of a path setbetween a VM of the Virtualized MME 100 and a VM of the Virtualized SGW120. For example, the Virtualized SGW 120 can establish sessions betweenthe Virtualized SGW 120 and a VM designated by the Virtualized MME 100by transmitting a message designating a TEID notified (i.e., sent) fromthe Virtualized MME 100 to the Virtualized MME 100. The informationindicating the VM at the transfer destination of the sessions may be anIP address and a GRE key.

Next, the Virtualized SGW 120 transmits a Modify Bearer Response messageto the Virtualized MME 100 (S12). The Virtualized MME 100 transmits aModify Bearer Request message for each of the sessions set in the S11 VMto be deleted.

Note that the sessions set between the Virtualized MME 100 and theVirtualized SGW 120 may be, for example, PDN connections. Further, whenthe S11 VM of the Virtualized MME 100 that should be deleted hassessions set between the S11 VM and a plurality of Virtualized SGWs, theVirtualized MME 100 transmits a Modify Bearer Request message to theplurality of Virtualized SGWs.

As explained above, the sessions set in the VM to be deleted can betransferred by performing the steps S11 and S12. In comparison to theprocess explained in the comparative example, the number of signalsnecessary for the transfer of sessions can be considerably reduced byperforming the process explained above with reference to the figure.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 25 . Similarly to FIG. 24 , FIG. 25 shows a processthat is performed when one of the S11 VMs 104-106 of the Virtualized MME100 is deleted. Further, while FIG. 24 shows a process in which a ModifyBearer Request message is transmitted for each session, FIG. 25 shows anexample in which an update process is performed for a plurality ofsessions at a time. Performing an update process for a plurality ofsessions at a time is called a “bulk process”.

A preparatory process for performing the bulk process is explained withreference to FIG. 25 . Firstly, the Virtualized MME 100 transmits aCreate Session Request message to the Virtualized SGW 120 when theVirtualized MME 100 establishes sessions between the Virtualized MME 100and the Virtualized SGW 120 in an S11 interface (S21). At this point,the Virtualized MME 100 transmits a CSID associated with a plurality ofsessions that are set by using the S11 VM 106 to the Virtualized SGW120. The CSID may have a value that is different for each of the VMs inwhich sessions are set.

The Virtualized SGW 120 recognizes that all of a plurality of sessionsfor which the same CSID is set are set in the same VM in the VirtualizedMME 100. The Virtualized SGW 120 transmits a Create Session Responsemessage as a response to the Create Session Request message (S22).

Next, the bulk process between the Virtualized MME 100 and theVirtualized SGW 120 is explained with reference to FIG. 26 . Firstly,the Virtualized MME 100 transmits an Update PDN Connection Set Requestmessage to the Virtualized SGW 120 when the Virtualized MME 100 deletesthe S11 VM 106 (S31). Note that the Virtualized MME 100 sets the CSIDassociated with the S11 VM 106, a group of IP addresses indicating VMsat the transfer destination of the sessions, and a group of TEIDs(Tunnel Endpoint IDs) in the Update PDN Connection Set Request message.The information indicating the VMs at the transfer destination of thesessions may be a group of IP addresses and a group of GRE keys.

Next, the Virtualized SGW 120 transmits an Update PDN Connection SetResponse message as a response to the Update PDN Connection Set Requestmessage (S32).

As explained below with reference to FIGS. 25 and 26 , by performing thebulk process, a plurality of sessions can be transferred from a VM inwhich they are currently set to another VM by transmitting/receiving oneUpdate PDN Connection Set Request message and one Update PDN ConnectionResponse message. In contrast to this, in the case of FIG. 24 , the samenumber of Modify Bearer Request messages and the same number of ModifyBearer Response messages as the number of set sessions need to betransmitted/received.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 27 . FIG. 27 shows a process that is performed whenone of the S1-MME VMs 109-111 of the Virtualized MME 100 is deleted.

Firstly, the Virtualized MME 100 transmits an MME CONFIGURATION UPDATEmessage to an eNodeB (S41). The Virtualized MME 100 sets an IP addressor other identification information indicating a VM at the transferdestination of the sessions in an MME CONFIGURATION UPDATE message.

Next, the eNodeB transmits an MME CONFIGURATION UPDATE ACKNOWLEDGEmessage to the Virtualized MME 100 as a response to the MMECONFIGURATION UPDATE message (S42). The Virtualized MME 100 transmits anMME CONFIGURATION UPDATE message for each of the sessions set in theS1-MME VM to be deleted.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 28 . FIG. 28 shows a process that is performed whenone of the S6a VMs 101-103 of the Virtualized MME 100 is deleted. Notethat steps S51 and S52 in FIG. 28 are similar to those in FIG. 27 exceptthat the entity with which the Virtualized MME 100 communicates is theHSS 21 and the names of transmitted/received signals are different fromthose in FIG. 27 . Therefore, their detailed descriptions are omittedhere. Further, as the transmitted/received signals, a Notify Requestmessage and a Notify Answer message are used.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 29 . FIG. 29 shows a process that is performed whenthe SGs VM 107 or 108 of the Virtualized MME 100 is deleted. Note thatsteps S61 and S62 in FIG. 29 are similar to those in FIG. 28 except thatthe entity with which the Virtualized MME 100 communicates is the VLR orthe MSC server 77, and therefore their detailed descriptions are omittedhere.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 30 . FIG. 30 shows a process that is performed whenthe S5/S8-CV VM 123 or 124 of the Virtualized SGW 120 is deleted. Notethat steps S71 and S72 in FIG. 30 are similar to those in FIG. 24 exceptthat the entity with which the Virtualized SGW 120 communicates is theVirtualized PGW 140, and therefore their detailed descriptions areomitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 31 . Similarly to FIG. 30 , FIG. 31 shows a processthat is performed when the S5/S8-CV VM 123 or 124 of the Virtualized SGW120 is deleted. Further, while FIG. 30 shows a process in which a ModifyBearer Request message is transmitted for each session, FIG. 31 shows anexample in which a bulk process is performed. Note that steps S81 andS82 in FIG. 31 are similar to those in FIG. 25 except that the entitywith which the Virtualized SGW 120 communicates is the Virtualized PGW140, and therefore their detailed descriptions are omitted here.

Further, steps S91 and S92 in FIG. 32 are also similar to those in FIG.26 except that the entity with which the Virtualized SGW 120communicates is the Virtualized PGW 140, and therefore their detaileddescriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 33 . FIG. 33 shows a process that is performed whenthe S5/S8-U VM 125 or 126 of the Virtualized SGW 120 is deleted. Notethat steps S101 and S102 in FIG. 33 are similar to those in FIG. 30except that sessions that are used for U-plane data communication of anS5/S8 interface are updated, and therefore their detailed descriptionsare omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 34 . Similarly to FIG. 33 , FIG. 34 shows a processthat is performed when the S5/S8-U VM 125 or 126 of the Virtualized SGW120 is deleted. Further, while FIG. 33 shows a process in which a ModifyBearer Request message is transmitted for each session, FIG. 34 shows anexample in which a bulk process is performed. Note that steps S111 andS112 in FIG. 34 are similar to those in FIG. 31 except that sessionsthat are used for U-plane data communication of an S5/S8 interface areupdated, and therefore their detailed descriptions are omitted here.

Further, steps S121 and S122 in FIG. 35 are also similar to those inFIG. 32 except that sessions that are used for U-plane datacommunication of an S5/S8 interface are updated, and therefore theirdetailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 36 . FIG. 36 shows a process that is performed when aVM that serves as an S4C interface of the Virtualized SGW 120 isdeleted. Note that steps S131 and S132 in FIG. 36 are similar to thosein FIG. 30 except that the entity with which the Virtualized SGW 120communicates is the SGSN 14, and therefore their detailed descriptionsare omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 37 . Similarly to FIG. 36 , FIG. 37 shows a processthat is performed when a VM that serves as an S4C interface of theVirtualized SGW 120 is deleted. Further, while FIG. 36 shows a processin which a Modify Bearer Request message is transmitted for eachsession, FIG. 37 shows an example in which a bulk process is performed.Note that steps S141 and S142 in FIG. 37 are similar to those in FIG. 34except that sessions that are set in the S4C interface are updated, andtherefore their detailed descriptions are omitted here.

Further, steps S151 and S152 in FIG. 38 are also similar to those inFIG. 35 except that sessions that are set in the S4C interface areupdated, and therefore their detailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 39 . FIG. 39 shows a process that is performed when aVM that serves as an S4U interface of the Virtualized SGW 120 isdeleted. Firstly, the Virtualized SGW 120 transmits a Modify BearerRequest message to the Virtualized SGSN 160 (S161). The Virtualized SGW120 transmits/receives a Modify Bearer Request message and after that aModify Bearer Response (step S164) through the S4C interface. TheVirtualized SGW 120 sets an IP address indicating a VM at the transferdestination of the sessions and a TEID in the Modify Bearer Requestmessage.

Next, the Virtualized SGSN 160 notifies the Virtualized RNC 210 of theupdate information of the VM serving as the S4U interface in theVirtualized SGW 120. Specifically, the Virtualized SGSN 160 transmits aRELOCATION REQUEST message to the Virtualized RNC 210 (S162). TheVirtualized SGSN 160 sets the information received in the step S161 inthe RELOCATION REQUEST message. The Virtualized RNC 210 transmits aRELOCATION REQUEST ACKNOWLEDGE message to the Virtualized SGSN 160 as aresponse to the RELOCATION REQUEST message (S163).

Upon receiving the RELOCATION REQUEST ACKNOWLEDGE message in the stepS163, the Virtualized SGSN 160 transmits a Modify Bearer Responsemessage to the Virtualized SGW 120 as a response to the Modify BearerRequest (S164). The Virtualized SGW 120 transmits a Modify BearerRequest message for each of the sessions set in the VM of the interfacerelated to the S4U to be deleted.

As explained above with reference to the figure, the Virtualized SGW 120does not directly notify the Virtualized RNC 210 of the informationabout the deletion of the VM, but can notify the Virtualized RNC 210 ofthe information about the deletion of the VM through the VirtualizedSGSN 160. In this way, the processing load of the Virtualized SGW 120for transmitting signals to the Virtualized RNC 210 can be reduced.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 40 . Similarly to FIG. 39 , FIG. 40 shows a processthat is performed when a VM that serves as an S4U interface of theVirtualized SGW 120 is deleted. Further, while FIG. 39 shows a processin which a Modify Bearer Request message is transmitted for eachsession, FIG. 40 shows an example in which a bulk process is performed.Note that steps S171 and S172 in FIG. 40 are similar to those in FIG. 37except that sessions that are set in the S4U interface are updated, andtherefore their detailed descriptions are omitted here.

Further, steps S181 and S184 in FIG. 41 are similar to those in FIG. 38except that sessions that are set in the S4U interface are updated, andtherefore their detailed descriptions are omitted here. Further, theVirtualized SGSN 160 repeats the steps S182 and S183 the same number oftimes as the number of set sessions. That is, the Virtualized SGW 120notifies the Virtualized SGSN 160 that a plurality of sessions arecollectively transferred to a new VM by using a bulk process. Incontrast to this, the Virtualized SGSN 160 does not use the bulk processand repeats the steps S182 and S183 the same number of times as thenumber of set sessions. When the Virtualized SGSN 160 has completed thenotification about the deletion of the VM in the Virtualized SGW 120 tothe Virtualized RNC 210 for all the sessions, the Virtualized SGSN 160transmits an Update PDN Connection Response message in a step S184.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 42 . FIG. 42 shows a process that is performed whenthe S11 VM 127 or 128 of the Virtualized SGW 120 is deleted. Note thatin steps S191 and S192 in FIG. 42 , the entity with which theVirtualized SGW 120 communicates is the Virtualized MME 100. Further,the Virtualized SGW 120 and the Virtualized MME 100 use an Update BearerRequest message and an Update Bearer Response message. The content ofeach of these messages is similar to that in FIG. 30 and therefore theirdetailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 43 . Similarly to FIG. 42 , FIG. 43 shows a processthat is performed when the S11 VM 127 or 128 of the Virtualized SGW 120is deleted. Further, while FIG. 42 shows a process in which a ModifyBearer Request message is transmitted for each session, FIG. 43 shows anexample in which a bulk process is performed.

In FIG. 43 , as a response to a Create Session Request messagetransmitted from the Virtualized MME 100 to the Virtualized SGW 120 in astep S201, the Virtualized SGW 120 transmits a Create Session Responsemessage to the Virtualized MME 100 (S202). The Virtualized SGW 120transmits a CSID associated with a plurality of sessions that are set inthe Create Session Response message by using the S11 VM 128 to theVirtualized SGW 120.

Note that steps S211 and S212 in FIG. 44 are similar to those in FIG. 38except that sessions set in the S11 VM 128 are updated and the entitywith which the Virtualized SGW 120 communicates is the Virtualized MME100, and therefore their detailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 45 . FIG. 45 shows a process that is performed whenthe S12 VM 131 or 132 of the Virtualized SGW 120 is deleted. Note thatsteps S221 to S224 in FIG. 45 are similar to those in FIG. 39 exceptthat the message used in the steps S221 and S224 is an Update BearerRequest message, and therefore their detailed descriptions are omittedhere.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 46 . Similarly to FIG. 45 , FIG. 46 shows a processthat is performed when the S12 VM 131 or 132 of the Virtualized SGW 120is deleted. Further, while FIG. 45 shows a process in which a ModifyBearer Request message is transmitted for each session, FIG. 46 shows anexample in which a bulk process is performed. Note that steps S231 andS232 in FIG. 46 are similar to those in FIG. 40 except that sessionsthat are set in the S12 VM 132 are updated, and therefore their detaileddescriptions are omitted here.

Further, steps S241 to S244 in FIG. 47 are also similar to those in FIG.41 except that sessions set in S12 VM 132 are updated, and thereforetheir detailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 48 . FIG. 48 shows a process that is performed whenthe S1-U VM 129 or 130 of the Virtualized SGW 120 is deleted. Note thatsteps S251 to S254 in FIG. 48 differ from those in FIG. 45 in that theentity with which the Virtualized SGW 120 communicates is theVirtualized MME 100 and the entity with which the Virtualized MME 100communicates is the Virtualized eNodeB 200. Further, FIG. 48 alsodiffers from FIG. 45 in that the message used in the steps S252 and S253is an E-RAB MODIFY REQUEST message. The content and the like set in themessage and other processes in FIG. 48 are similar to those in FIG. 45 ,and therefore their detailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 49 . Similarly to FIG. 48 , FIG. 49 shows a processthat is performed when the S1-U VM 129 or 130 of the Virtualized SGW 120is deleted. Further, while FIG. 48 shows a process in which a ModifyBearer Request message is transmitted for each session, FIG. 49 shows anexample in which a bulk process is performed. Steps S261 and S262 inFIG. 49 are similar to the steps S201 and S202 in FIG. 43 except that aCSID associated with the S1-U VM 130 is notified (i.e., sent), andtherefore their detailed descriptions are omitted here.

Further, steps S272 to S274 in FIG. 50 are also similar to those in FIG.48 except that a bulk process is performed in the steps S271 and S274,and therefore their detailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 51 . FIG. 51 shows a process that is performed whenthe Gxx VMs 121 and 122 of the Virtualized SGW 120 are deleted. Notethat in a step S281 in FIG. 51 , the V-PCRF 52 is notified of the factthat the Gxx VMs will be deleted by using a CCR message. Further, theV-PCRF 52 transmits a CCA message to the Virtualized SGW 120 as aresponse (S282).

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 52 . FIG. 52 shows a process that is performed whenthe S5/S8-C VM 149 or 150 of the Virtualized PGW 140 is deleted. Notethat the processes in FIG. 52 are similar to those explained in FIG. 30except that the transmission source of each signal is interchanged withthe transmission destination thereof, and therefore their detaileddescriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 53 . FIG. 53 shows a process that is performed whenthe S5/S8-C VM 149 or 150 of the Virtualized PGW 140 is deleted. In FIG.53 , in order to perform a bulk process, the Virtualized PGW 140transmits a Create Session Response message to the Virtualized SGW 120as a response to a Create Session Request message transmitted in thestep S301 (S302). The Virtualized PGW 140 sets a CSID associated withthe S5/S8-C VM 150 in the Create Session Response message.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 54 . FIG. 54 shows a process that is performed whenthe S5/S8-C VM 150 of the Virtualized PGW 140 is deleted. Note that theprocesses in FIG. 54 are similar to those explained in FIG. 32 exceptthat the transmission source of each signal is interchanged with thetransmission destination thereof, and therefore their detaileddescriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 55 . FIG. 55 shows a process that is performed whenthe S5/S8-U VM 151 or 152 of the Virtualized PGW 140 is deleted. Notethat the processes in FIG. 55 are similar to those explained in FIG. 33except that the transmission source of each signal is interchanged withthe transmission destination thereof, and therefore their detaileddescriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIGS. 56 and 57 . FIGS. 56 and 57 show a process that isperformed when the S5/S8-U VM 152 of the Virtualized PGW 140 is deleted.Note that the processes in FIG. 56 are similar to those explained inFIG. 34 except that the transmission source of each signal isinterchanged with the transmission destination thereof, and thereforetheir detailed descriptions are omitted here. Further, the processes inFIG. 57 are similar to those explained in FIG. 35 except that thetransmission source of each signal is interchanged with the transmissiondestination thereof, and therefore their detailed descriptions areomitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 58 . FIG. 58 shows a process that is performed whenthe SGi VM 147 or 148 of the Virtualized PGW 140 is deleted. TheVirtualized PGW 140 sets the deletion of the SGi VM 1 in an Updaterouting table message and transmits the Update routing table message toa TDF, a SDN, or the like included in the operator network 18 (S351).Further, the Virtualized PGW 140 receives an Update routing acknowledgemessage as a response to the Update routing table message (S352).

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 59 . FIG. 59 shows a process that is performed whenone of the Gx VMs 141-143 of the Virtualized PGW 140 is deleted. Theprocesses in FIG. 59 are similar to those in FIG. 51 except that one ofthe Gx VMs 141-143 is deleted, and therefore their detailed descriptionsare omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 60 . FIG. 60 shows a process that is performed whenone of the Gy/Gz VMs 144-146 of the Virtualized PGW 140 is deleted. TheVirtualized PGW 140 transmits a Notify Request message in which a VM towhich the sessions of the deleted VM have been transferred is set to theOCS 58 (S371). The Virtualized PGW 140 receives a Notify Answer messageas a response to the Notify Request message from the OSC 58 (S372).Further, similarly to FIG. 60 , FIG. 61 shows a process that isperformed when one of the Gy/Gz VMs 144-146 of the Virtualized PGW 140is deleted. In FIG. 61 , the entity with which the Virtualized PGW 140communicates is the OFCS 60.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 62 . FIG. 62 shows a process that is performed whenthe S4-C VM 161 or 162 of the Virtualized SGSN 160 is deleted. Note thatthe processes in FIG. 62 are similar to those explained in FIG. 36except that the transmission source of each signal is interchanged withthe transmission destination thereof, and therefore their detaileddescriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIGS. 63 and 64 . FIGS. 63 and 64 show a process that isperformed when the S4-C VM 162 of the Virtualized SGSN 160 is deleted.Note that the processes in FIG. 63 are similar to those explained inFIG. 37 except that the transmission source of each signal isinterchanged with the transmission destination thereof, and thereforetheir detailed descriptions are omitted here. Further, the processes inFIG. 64 are similar to those explained in FIG. 38 except that thetransmission source of each signal is interchanged with the transmissiondestination thereof, and therefore their detailed descriptions areomitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 65 . FIG. 65 shows a process that is performed whenthe S4-U VM 169 or 170 of the Virtualized SGSN 160 is deleted. Note thatthe processes in FIG. 62 are similar to those explained in FIG. 39except that the transmission source of each signal is interchanged withthe transmission destination thereof in the steps S161 and S164, i.e.,in the communication between the Virtualized SGSN 160 and theVirtualized PGW 140 explained above with reference to FIG. 39 , andtherefore their detailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIGS. 66 and 67 . FIGS. 66 and 67 show a process that isperformed when the S4-U VM 170 of the Virtualized SGSN 160 is deleted.Note that the processes in FIG. 66 are similar to those explained inFIG. 40 except that the transmission source of each signal isinterchanged with the transmission destination thereof, and thereforetheir detailed descriptions are omitted here. Further, the processes inFIG. 67 are similar to those explained in FIG. 41 except that thetransmission source of each signal is interchanged with the transmissiondestination thereof in the steps S181 and S184, i.e., in thecommunication between the Virtualized SGSN 160 and the Virtualized PGW140 explained above with reference to FIG. 41 , and therefore theirdetailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 68 . FIG. 68 shows a process that is performed whenthe Iu-C VM 173 or 174 of the Virtualized SGSN 160 is deleted.

The Virtualized SGSN 160 transmits an Iu UPDATE Request message to theVirtualized RNC 210 (S451). The Virtualized SGSN 160 sets informationabout a VM at the transfer destination of the sessions after thedeletion of the Iu-C VM 173 or 174 in an Iu UPDATEREQUEST message. Next,the Virtualized SGSN 160 receives an Iu UPDATE ACKNOWLEDGE message as aresponse to the Iu UPDATEREQUEST message (S452).

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 69 . FIG. 69 shows a process that is performed whenthe Iu-U VM 175 or 176 of the Virtualized SGSN 160 is deleted.

The Virtualized SGSN 160 transmits a RELOCATION Request message to theVirtualized RNC 210 (S461). The Virtualized SGSN 160 sets informationabout a VM at the transfer destination of the sessions after thedeletion of the Iu-U VM 175 or 176 in a RELOCATION Request message.Next, the Virtualized SGSN 160 receives a RELOCATION REQUEST ACKNOWLEDGEmessage as a response to the RELOCATION Request message (S462).

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIGS. 70 and 71 . FIGS. 70 and 71 show a process that isperformed when the Iu-U VM 176 of the Virtualized SGSN 160 is deleted.

In FIG. 70 , the Virtualized SGSN 160 transmits a RAB ASSIGNMENT Requestmessage to the Virtualized RNC 210 (S471). The Virtualized SGSN 160 setsa CSID associated with the Iu-U VM 176 in the RAB ASSIGNMENT Requestmessage. The Virtualized SGSN 160 receives a RAB ASSIGNMENT RESPONSEmessage as a response to the RAB ASSIGNMENT Request message (S472).

FIG. 71 shows that the Virtualized SGSN 160 and the Virtualized RNC 210perform a bulk process related to the deletion of the Iu-U VM 176 byusing an Update PDN Connection Set Request message and the Update PDNConnection Response message.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 72 . FIG. 72 shows a process that is performed whenthe Gr/S6d VM 167 or 168 of the Virtualized SGSN 160 is deleted. Notethat the processes in FIG. 72 are similar to those explained in FIG. 28except that the Virtualized MME 100 in FIG. 28 is replaced by theVirtualized SGSN 160. Further, in FIG. 73 , an Any Time ModificationRequest message and an Any Time Modification Response message are usedinstead of the Notify Request message and the Notify Answer message usedin FIG. 72 .

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 74 . FIG. 74 shows a process that is performed whenthe Gn-C VM 163 or 164 of the Virtualized SGSN 160 is deleted.

The Virtualized SGSN 160 transmits an Update PDP context Request messageto the Virtualized GGSN 180 (S511). The Virtualized SGSN 160 setsinformation about a VM at the transfer destination of the sessions afterthe deletion of the Gn-C VM 163 or 164 in an Update PDP context Requestmessage. Next, the Virtualized SGSN 160 receives an Update PDP contextResponse message as a response to the Update PDP context Request message(S512).

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIGS. 75 and 76 . FIGS. 75 and 76 show a process that isperformed when the Gn-C VM 164 of the Virtualized SGSN 160 is deleted.

In FIG. 75 , the Virtualized SGSN 160 transmits a Create PDP contextRequest message to the Virtualized GGSN 180 (S521). The Virtualized SGSN160 sets a CSID associated with the Gn-C VM 164 in the Create PDPcontext Request message. The Virtualized SGSN 160 receives a Create PDPcontext Response message as a response to the Create PDP context Requestmessage (S522).

FIG. 76 shows that the Virtualized SGSN 160 and the Virtualized GGSN 180perform a bulk process related to the deletion of the Gn-C VM 164 byusing an Update PDN Connection Set Request message and the Update PDNConnection Response message.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 77 . FIG. 77 shows a process that is performed whenthe Gn-U VM 165 or 166 of the Virtualized SGSN 160 is deleted. Note thatthe operation in FIG. 77 is similar to that in FIG. 74 except that theGn-U VM, instead of the Gn-C VM, is updated in the process, andtherefore their detailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIGS. 78 and 79 . FIGS. 78 and 79 show a process that isperformed when the Gn-U VM 166 of the Virtualized SGSN 160 is deleted.Note that the processes in FIGS. 78 and 79 are similar to those in FIGS.75 and 76 except that the Gn-U VM is updated, and therefore theirdetailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 80 . FIG. 80 shows a process that is performed whenthe Gs VM 171 or 172 of the Virtualized SGSN 160 is deleted. Note thatthe processes in FIG. 80 are similar to those explained in FIG. 29except that the Gs VM is updated, and therefore their detaileddescriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 81 . FIG. 81 shows a process that is performed whenthe Gn-C VM 189 or 190 of the Virtualized GGSN 180 is deleted. Note thatthe processes in FIG. 81 are similar to those explained in FIG. 74except that the transmission source of each signal is interchanged withthe transmission destination thereof, and therefore their detaileddescriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIGS. 82 and 83 . FIGS. 82 and 83 show a process that isperformed when the Gn-C VM 190 of the Virtualized GGSN 180 is deleted.

In FIG. 82 , the Virtualized SGSN 160 transmits a Create PDP contextRequest message to the Virtualized GGSN 180 (S591). Next, theVirtualized GGSN 180 transmits a Create PDP context Response message tothe Virtualized SGSN 160 as a response to the Create PDP context Requestmessage (S592). The Virtualized GGSN 180 sets a CSID associated with theGn-C VM 190 in the Create PDP context Response message.

FIG. 83 shows that the Virtualized SGSN 160 and the Virtualized GGSN 180perform a bulk process related to the deletion of the Gn-C VM 190 byusing an Update PDN Connection Set Request message and the Update PDNConnection Response message.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 84 . FIG. 84 shows a process that is performed whenthe Gn-U VM 191 or 192 of the Virtualized GGSN 180 is deleted. Note thatthe processes in FIG. 84 are similar to those explained in FIG. 77except that the transmission source of each signal is interchanged withthe transmission destination thereof, and therefore their detaileddescriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIGS. 85 and 86 . FIGS. 85 and 86 show a process that isperformed when the Gn-U VM 192 of the Virtualized GGSN 180 is deleted.

Processes in FIG. 85 are similar to those explained in FIG. 82 exceptthat the Virtualized GGSN 180 transmits the CSID related to the Gn-U VM192 to the Virtualized SGSN 160, and therefore their detaileddescriptions are omitted here.

FIG. 86 shows that the Virtualized SGSN 160 and the Virtualized GGSN 180perform a bulk process related to the deletion of the Gn-U VM 192 byusing an Update PDN Connection Set Request message and the Update PDNConnection Response message.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 87 . FIG. 87 shows a process that is performed whenthe Gi VM 187 or 188 of the Virtualized GGSN 180 is deleted. Note thatthe processes in FIG. 87 are similar to those explained in FIG. 58except that the Virtualized GGSN 180 is used in place of the VirtualizedPGW 140, and therefore their detailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 88 . FIG. 88 shows a process that is performed whenone of the Gx VMs 181 to 183 of the Virtualized GGSN 180 is deleted.Note that the processes in FIG. 88 are similar to those explained inFIG. 59 except that the Virtualized GGSN 180 is used in place of theVirtualized PGW 140, and therefore their detailed descriptions areomitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 89 . FIG. 89 shows a process that is performed whenone of the Gy/Gz VMs 184 to 186 of the Virtualized GGSN 180 is deleted.Note that the processes in FIG. 89 are similar to those explained inFIG. 60 except that the Virtualized GGSN 180 is used in place of theVirtualized PGW 140, and therefore their detailed descriptions areomitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 90 . FIG. 90 shows a process that is performed whenone of the Gy/Gz VMs 184 to 186 of the Virtualized GGSN 180 is deleted.Note that the processes in FIG. 90 are similar to those explained inFIG. 61 except that the Virtualized GGSN 180 is used in place of theVirtualized PGW 140, and therefore their detailed descriptions areomitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 91 . FIG. 91 shows a process that is performed whenone of the S1-MME VMs 201 to 203 of the Virtualized eNodeB 200 isdeleted.

The Virtualized eNodeB 200 transmits an eNB CONFIGURATION UPDATE messageto the Virtualized MME 100 (S681). The Virtualized eNodeB 200 setsinformation about a VM at the transfer destination of the sessions afterthe deletion of one of the S1-MME VMs 201 to 203 in an eNB CONFIGURATIONUPDATE message. Next, the Virtualized eNodeB 200 receives an eNBCONFIGURATION UPDATE ACKNOWLEDGE message as a response to the eNBCONFIGURATION UPDATE message (S682).

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 92 . FIG. 92 shows a process that is performed whenone of the S1-U VMs 204 to 206 of the Virtualized eNodeB 200 is deleted.

Firstly, the Virtualized eNodeB 200 transmits an E-RAB MODIFY Requestmessage to the Virtualized MME 100 (S691). The Virtualized eNodeB 200sets information about a VM at the transfer destination of the sessionsafter the deletion of one of the S1-U VMs 204 to 206 in an E-RAB MODIFYRequest message. Note that the Virtualized eNodeB 200 transmits theE-RAB MODIFY Request message through an S1-MME interface.

Next, the Virtualized MME 100 transmits the Modify Bearer Requestmessage in which the information notified (i.e., sent) from theVirtualized eNodeB 200 is set to the Virtualized SGW 120 (S692). Next,the Virtualized MME 100 receives a Modify Bearer Response message fromthe Virtualized SGW 120 as a response to the Modify Bearer Requestmessage (S693). Next, the Virtualized MME 100 transmits an E-RAB MODIFYACKNOWLEDGE message to the Virtualized eNodeB 200 as a response to theModify Bearer Request message (S694).

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIGS. 93 and 94 . FIGS. 93 and 94 show a process that isperformed when the S1-U VM 206 of the Virtualized eNodeB 200 is deleted.

Firstly, the Virtualized eNodeB 200 transmits an Initial Context SetupResponse message to the Virtualized MME 100 as a response to the InitialContext Setup Request message received in the step S701 (S702). TheVirtualized eNodeB 200 sets a CSID associated with the S1-U VM 206 inthe Initial Context Setup Response message. The Virtualized MME 100notifies the Virtualized SGW 120 of the CSID notified (i.e., sent) fromthe Virtualized eNodeB 200 by transmitting/receiving a Modify BearerRequest message (S703) and a Modify Bearer Response message (S704).

In FIG. 94 , when the Virtualized eNodeB 200 deletes the S1-U VM 206,the Virtualized eNodeB 200 transmits an Update PDN Connection SetRequest message to the Virtualized MME 100. The Virtualized eNodeB 200sets a CSID associated with the S1-U VM 206 to be deleted in the UpdatePDN Connection Set Request message (S711).

Next, when the Virtualized MME 100 receives the Update PDN ConnectionSet Request message with the CSID set therein, the Virtualized MME 100transmits a Modify Bearer Request message to the Virtualized SGW 120 fora plurality of sessions associated with the CSID at a time (S712) andreceives a Modify Bearer Response message as its response (S713). Thatis, the Virtualized MME 100 repeats the steps S712 and S713 until theprocesses for all the sessions have been completed.

When the processes for all the sessions have been completed, theVirtualized MME 100 transmits an Update PDN Connection Response messageto the Virtualized eNodeB 200 (S714).

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 95 . FIG. 95 shows a process that is performed whenone of the Iu-C VMs 211 to 213 of the Virtualized RNC 210 is deleted.Note that the processes in FIG. 95 are similar to those explained inFIG. 68 except that the transmission source of each signal isinterchanged with the transmission destination thereof, and thereforetheir detailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIG. 96 . FIG. 96 shows a process that is performed whenone of the Iu-U VMs 214 to 216 of the Virtualized RNC 210 is deleted.Note that the processes in FIG. 96 are similar to those explained inFIG. 69 except that the transmission source of each signal isinterchanged with the transmission destination thereof, and thereforetheir detailed descriptions are omitted here.

Next, a flow of a session information update process according to thesecond exemplary embodiment of the present invention is explained withreference to FIGS. 97 and 98 . FIGS. 97 and 98 show a process that isperformed when the Iu-U VM 216 of the Virtualized RNC 210 is deleted.

In FIG. 97 , firstly, the Virtualized RNC 210 transmits a RAB AssignResponse message to the Virtualized SGSN 160 as a response to the RABAssign Request message received in the step S741 (S742). The VirtualizedRNC 210 sets a CSID associated with the Iu-U VM 216 in the RAB AssignResponse message.

FIG. 98 shows a bulk process between the Virtualized RNC 210 and theVirtualized SGSN 160. Note that the processes in FIG. 98 are similar tothose explained in FIG. 71 except that the transmission source of eachsignal is interchanged with the transmission destination thereof, andtherefore their detailed descriptions are omitted here.

As explained above, by using the communication process according to thesecond exemplary embodiment of the present invention, it is possible,when a given VM is to be deleted, to notify the counterpart node deviceof the VM to which the sessions are transferred. As a result, thecounterpart node device can communicates, for the node device in whichthe VM is changed, with the VM to which the sessions are transferred.Therefore, since a VM transfer process can be performed in neighboringnode devices, there is no need to make a terminal device perform aDetach process and the like which would otherwise have to be performedwhen the transfer of a VM is performed. Consequently, since there is noneed to perform the Detach process and the like, the number of controlsignals that occur in the communication network can be reduced.

Although the present invention is described as a hardware configurationin the above-described exemplary embodiments, the present invention isnot limited to the hardware configurations. In the present invention, aprocess flow explained with reference to a respective figure can be alsoimplemented by causing a CPU (Central Processing Unit) to execute acomputer program.

In the above-described examples, the program can be stored in varioustypes of non-transitory computer readable media and thereby supplied tocomputers. The non-transitory computer readable media includes varioustypes of tangible storage media. Examples of the non-transitory computerreadable media include a magnetic recording medium (such as a flexibledisk, a magnetic tape, and a hard disk drive), a magneto-optic recordingmedium (such as a magneto-optic disk), a CD-ROM (Read Only Memory), aCD-R, and a CD-R/W, and a semiconductor memory (such as a mask ROM, aPROM (Programmable ROM), an EPROM (Erasable PROM), a flash ROM, and aRAM (Random Access Memory)). Further, the program can be supplied tocomputers by using various types of transitory computer readable media.Examples of the transitory computer readable media include an electricalsignal, an optical signal, and an electromagnetic wave. The transitorycomputer readable media can be used to supply programs to computerthrough a wire communication path such as an electrical wire and anoptical fiber, or wireless communication path.

Note that the present invention is not limited to the aforementionedexemplary embodiments and may be changed as appropriate withoutdeparting from the spirit of the present invention.

Although the present invention is explained with reference to exemplaryembodiments, the present invention is not limited to the above-describedexemplary embodiments. Various modifications that can be understood bythose skilled in the art can be made to the configuration and details ofthe present invention within the scope of the invention.

This application is based upon and claims the benefit of priority fromJapanese patent applications No. 2014-25566, filed on Feb. 13, 2014, thedisclosure of which is incorporated herein in its entirety by reference.

REFERENCE SIGNS LIST

1 COMMUNICATION DEVICE

2 COMMUNICATION DEVICE

3 VM

4 VM

5-8 COMMUNICATION RESOURCE

10 UE

11 E-UTRAN

12 MME

13 SGW

14 SGSN

15 HSS

16 PGW

17 PCRF

18 OPERATOR NETWORK

21 HSS

22 PGW

23 PCRF

24 OPERATOR NETWORK

31 TE

32 MT

33 UTRAN

34 SGSN

35 TE

36 MT

37 BSS

38 SGSN

39 GGSN

40 GGSN

41 MSC/VLR

42 SMS-GMSC, SMS-IWMSC

43 SMS-SC

44 gsmSCF

45 CGF

46 EIR

47 Billing System

48 TE

49 HLR

51 BBERF

52 V-PCRF

53 SPR

54 H-PCRF

55 PCEF

56 Gateway

57 AF

58 OCS

59 TDF

60 OFCS

71 UE

72 E-UTRAN

73 GERAN

74 UTRAN

75 SGSN

76 MME

77 MSC Server

100 Virtualized MME

101-106 S6a VM

107, 108 SGs VM

109-111 S1-MME VM

120 Virtualized SGW

121, 122 Gxx VM

123, 124 S5/S8-C VM

125, 126 S5/S8-U VM

127, 128 S11 VM

129, 130 S1-U VM

131, 132 S12 VM

140 Virtualized PGW

141-143 Gx VM

144, 145 Gy/Gz VM

146 Gy/Gz VM

147, 148 SGi VM

149, 150 S5/S8-C VM

151, 152 S5/S8-U VM

160 Virtualized SGSN

161, 162 S4-C VM

163, 164 Gn-C VM

165, 166 Gn-U VM

167, 168 Gr/S6d VM

169, 170 S4-U VM

171, 172 Gs VM

173, 174 Iu-C VM

175, 176 Iu-U VM

180 Virtualized GGSN

181-183 Gx VM

184, 185 Gy/Gz VM

186 Gy/Gz VM

187, 188 Gi VM

189, 190 Gn-C VM

191, 192 Gn-U VM

200 Virtualized eNodeB

201-203 S1-MME VM

204-206 S1-U VM

207 LTE-Uu

210 Virtualized RNC

211-213 Iu-C VM

214-216 Iu-U VM

217 Uu

The invention claimed is:
 1. A first virtualized communication deviceused in a mobile communication system, the first virtualizedcommunication device comprising: a controller configured to establish asession between communication devices; and a transmitter configured tosend information about a second virtualized communication deviceconfigured to establish a session between communication devices to amobility management device configured to perform mobility management ofa terminal device, wherein the transmitter sends information about thesecond virtualized communication device for establishing a new sessionbetween communication devices to the mobility management device during atransfer procedure from the first virtualized communication device tothe second virtualized communication device, and wherein the controllerreleases the session established by the first virtualized communicationdevice after the new session is re-established by the second virtualizedcommunication device identified by the information.
 2. A method for afirst virtualized communication device used in a mobile communicationsystem, the method comprising: establishing a session betweencommunication devices; during a transfer procedure, sending informationabout a second virtualized communication device for establishing a newsession between communication devices to a mobility management deviceconfigured to perform mobility management of a terminal device; andreleasing the session established by the first virtualized communicationdevice after the new session is re-established by the second virtualizedcommunication device identified by the information.